Microsoft Office setup has various products for various purposes.These versions include office setup 2016, office setup 365, office setup Home & Student and much more. For All these products you will need a Microsoft office account to access the full features of office setup.
If you use services like Outlook, OneDrive, & Skype then you should definitely have a Microsoft account. Recommended links for installing Microsoft office setup are office.com/setup, setup.office.com, www.office.com/setup.